Ultra short wave antenna system



Aug. 30, 1932. c. w. HANSELL ULTRA SHORT WAVE ANTENNA SYSTEM Filed July21. 1930 INVENTOR CLARENCE W. HANSELL BY 17%? ATTORNEY Patented Aug. 30,1932 NITED STATE P'rsr Fries CLARENCE W. HAN SELL, OF PORT JEFFERSON,NEW YORK, ASSIGNOR T0 RADIO CORPO- RATION OF AMERICA, A CORPORATION OFDELAWARE ULTRA SHORT WAVE ANTENNA SYSTEM Application filed July 21,

This invention relates to antennae and especially towards the provisionof an ultra short wave antennae utilizing the directive properties of aparabolic reflector.

Although parabolic reflectors have been used in combination withantennae, the combination is directive mainly in a plane perpendicularto the longitudinal axis of the reflector. To improve the directivecharacteristic of the system in a direction along the axis of thereflector, is one of the objects of my present invention and this I doby utilizing in combination with a reflector a linear conductor, radiantaction along alternate half wave length portions of which is suppressed.In this manner, each of the working portions of the conductor, one-halfwave length long carry currents of like phase, which tend to concentrateelectromagnetic Wave action in a direction along the axis of thereflector.

Still a further object of my invention is to provide a simple supportfor the conductor within the reflector and this I do by supporting theconductor with insulators directly on the reflector.

Although I have defined my invention with particularity in the appendedclaims, the invention itself both as to its structural organization andmode of operation may best be understood by referring to theaccompanying drawing which is given by way of illustration only of thefeatures of my invention.

Turning to the drawing, I provide the combination of ametallic reflector2 with a conductor 4 folded upon itself in U-shaped loops 6 at alternatehalf wave lengths. The portions 8 of the conductor parallel to thelongitudinal axis of the reflector 2 constitute the active portion ofthe conductor for electromagnetic wave transmission or reception. Theportions 8 will carry currents in phase, as they constitute alternatehalf wave lengths of the conductor 4, and will increase the directivityof the system along the longitudinal axis of the reflector 2.

The loops 6, being folded upon themselves will be substantiallynon-active with respect to electromagnetic waves. Coupling may beestablished to the conductor 4 through an in- 1930. Serial No. 469,415.

termediate loop by means of suitable leads 10 leading to radio apparatus12 either transmitting or receiving.

In order to provide for the simple support of the radiating element orconductor 4' within the reflector 2, insulators 14 suitably mountedwithin the reflector are provided through which the loops 6 pass.Although the active portions of the radiator 4 should be placedone-quarter wave parabolic reflector 2 for best theoretical action, inpractice, the spacing is not critical. Consequently any variationtherefrom such as may be caused by passing the half wave length loops 6through the insulators 14, does not affect, too adversely the action ofthe ultra short wave antenna system described. It is only necessary thatthe radiators 8 be close to the focal point fleeting action.

Having thus described my invention, what I claim is 1. In combination, aconductor, a plurality of wave lengths long having U-shaped loopsone-half wave length long at wave lengths thereof, and a parabolicreflector, associated with and insulated from said conductor, forrendering electromagnetic action of the conductor substantiallyundirectional, said reflector being constructed at cer tain portionsthereof to receive the U-shaped loops for supporting said conductor.

2. In combination, a linear conductor, having U-shaped loops one-halfwave length long at alternate half wave lengths along the axisof theconductor, and, a parabolic reflector associated therewith andconstructed to hold the conductor in fixed relation with respect to saidreflector, the loops of the conductor being arranged to support theconductor on the parabolic reflector.

3. In combination, a linear conductor having U-shaped loops one-halfwave length long at alternate half wave lengths along the axis of theconductor, and, a parabolic reflector associated therewith andconstructed to hold the conductor in fixed relation with respect to saidreflector by means of insulators mounted in the reflector, the loops ofsaid conlength from the alternate halfof the reflector for good re- M 77a 4. In combination, a linear antenna element 1 havlng non-rad1ating-portions at alternate V 5 half Wave lengths along its length, aparabolic ductor-being arranged to pass through said insulators,

" .reflector therefor, and means for supporting i ing non-radiating Ithe elementupon the reflector at the non-ray diating portions in suchnon-radiating portions extend through id refle tor; 5. In comblnatlon, alinear conductor havductor, a parabolic refiectorassoeiated therewithand having insulating members mounted in the reflector and spacedpredetermined dis- 'tances apart, said U-shaped loops: being. ar-

ranged to pass through said insulating IneInhers and to extend throughsaid reflector; and

'I said members being constructed tofirmly se- 7 cure said loops to saidreflector.

c, CLARENCE W; HANSELL.

manner that said 7 U-shaped loops at alternate half Wave lengths alongth axi o the M or

